How much coffee is too much coffee?

People with heart problems often hear that they should reduce their coffee consumption, A new study found that drinking two to three glasses a day is actually good for you.

 Coffee (photo credit: INGIMAGE)
(photo credit: INGIMAGE)

In recent years, more and more studies have found that drinking a few cups of coffee a day contributes greatly to health. Now, a new study has found that drinking two to three cups of coffee a day may reduce the risk of developing heart problems – and can even prolong life.

Researchers analyzed data from nearly 400,000 people in their 50s without heart disease and followed them for a decade. They found that drinking two or three cups of coffee each day was best, with those people exhibiting a 10% to 15% lower risk of developing coronary heart disease, heart failure and irregular heartbeat.

The benefits were present regardless of whether they drank instant or ground coffee. Decaffeinated coffee, on the other hand, didn’t yield the same health benefits.

The researchers also analyzed people who had already experienced some heart problems and found that two to three cups a day were connected to a lower chance of dying compared to not drinking any at all, despite fears among doctors that the stimulation from caffeine might worsen heart problems.

"Our data suggest that daily coffee consumption should be included as part of a healthy diet for people with and without heart disease," said study leader Prof. Peter Kistler, an expert at the Baker Heart and Diabetes Institute in Melbourne, Australia.

 Cup of coffee (credit: INGIMAGE) Cup of coffee (credit: INGIMAGE)

What is in coffee?

Coffee beans contain more than 100 compounds associated with lower levels of inflammation and increased metabolism.

The researchers said these mechanisms may be some of the factors behind why coffee can improve heart health. These compounds can reduce inflammation, and improve insulin sensitivity, which lowers blood sugar and increases metabolism. Caffeine also suppresses appetite, which can lead to a lower rate of obesity and the health problems associated with it.

The researchers used data from BioBank in the UK, a database containing health information of more than half a million Britons who have been tracked for a decade. Participants filled out a questionnaire in which they were asked, among other things, how many cups of coffee they drink a day. In the first study, the team examined data on 382,535 people, with an average age of 57 and no heart problems.

Study results, which will be presented at the American Conference on Cardiology in Washington, DC, show that drinking two to three glasses a day provides the greatest benefit. By the end of the study, the risk of the subjects suffering from coronary heart disease, heart failure, heart rhythm problems or death for any reason was 10% to 15% lower.

The team also found that those who drank one cup of coffee a day were at the lowest risk of having a stroke or dying of heart problems. Kistler, head of arrhythmia research at Alfred Hospital and at Baker, said there is a "whole range of mechanisms through which coffee may improve heart health and reduce mortality."

In the second part of the study, the team examined 34,279 people with cardiovascular disease to determine how coffee consumption affected their health.

Overall, those who drank two to three cups of coffee each day had the lowest chance of dying over a 10-year period – and drinking any amount of coffee didn’t increase the risk of developing heart rhythm problems, which some doctors cite as a reason to reduce coffee consumption, as it causes rapid heartbeat and palpitations.

The team found that those who suffered from atrial fibrillation, a common heart rhythm problem, and drank one cup of coffee a day were almost 20% less likely to die during 10 years of follow-up compared to those who didn’t drink coffee.

Kistler said doctors "usually have a certain concern" about people drinking coffee and suffering from cardiovascular disease or arrhythmias. He concluded that their research shows that drinking coffee daily is safe and can be part of a healthy diet – specifically for people with heart disease.